explain select i_item_id, avg(cs_quantity) agg1, avg(cs_list_price) agg2, avg(cs_coupon_amt) agg3, avg(cs_sales_price) agg4 from catalog_sales, customer_demographics, date_dim, item, promotion where catalog_sales.cs_sold_date_sk = date_dim.d_date_sk and catalog_sales.cs_item_sk = item.i_item_sk and catalog_sales.cs_bill_cdemo_sk = customer_demographics.cd_demo_sk and catalog_sales.cs_promo_sk = promotion.p_promo_sk and cd_gender = 'F' and cd_marital_status = 'W' and cd_education_status = 'Primary' and (p_channel_email = 'N' or p_channel_event = 'N') and d_year = 1998 group by i_item_id order by i_item_id limit 100;
